In an exclusive interview with the Sunday People , Nicole’s mum Mary lays bare the astonishing way her daughter found out about the ex-Oasis frontman’s infidelity.

And she also reveals that callous Liam, 40, hasn’t rung the All Saints singer once since being forced to break the news to her while partying hard in Ibiza where he was performing with his band Beady Eye.

“She said to me, ‘Mum, he hasn’t even called to ask how the boys are.’

“She said ‘I’ve got a text, Mum, that says ‘I wish I could be with you.’ He’s probably so out of it and so off his head that he doesn’t know what day it is.”

Liam made the heartbreaking call to Nicole, the mother of his 11-year-old son Gene, on Wednesday – just hours before it emerged he is the mystery rocker said to have fathered a child with American showbiz journalist Liza Ghorbani.

Blonde Liza, 39, looks astonishingly like Liam’s wife.

(Photo: Rex)

At the time of the call, Nicole was ­enjoying the first day of a family holiday with her three sisters Lori, Lee, and former All Saints co-star Natalie, 40.

Also with them was the couple’s son Gene, Liam’s other son Lennon, 13, whom he fathered with first wife Patsy Kensit, and Liam’s mum Peggy.

Still struggling to come to terms with her son-in-law’s betrayal, Mary said: “It’s such a shock. There was no ­warning, it was the last thing Nikki ­expected. It came out of the blue.

“He phoned her the day before it came out in the paper here to tell her. She had been talking about it. Nat and Nic and their hairdresser were together – the girls were ­getting their hair done.

“They were sitting together trying to guess who the rock star was, ­saying, ‘Do you think it might be so-and-so?’ They’re normal girls.

“Nat was telling me that when he called and told her, Nikki went down on her knees and said, ‘It’s Liam, it’s Liam.’ Nat knew what she meant because they had been talking about it.”

Mary, of Hampstead, north London, added: “Until then Nikki didn’t have a clue.

“She went on the holiday ahead of Liam because he still had a couple of gigs in Spain.

“Liam has airline tickets to join them, but obviously he’s not going now, at least I wouldn’t think so.”

Liam is said to have had a fling with Liza ­before ditching her when she was pregnant with a daughter, now seven months old.

The pair reportedly met when she ­interviewed him for the New York Times in 2010.

(Photo: Getty)

Liam is being sued by her in the Manhattan Family Court for £2million child support. Earlier this week he was seen in Ibiza wearing a T-shirt plastered with the words Baby F*** Off from a 1977 punk song by Wayne County & the Electric Chairs.

Mum-in-law Mary said: “With his type of lifestyle they get everything handed to them on a plate and it’s out of reality.

“But I don’t want to say anything bad against him. This isn’t just like a six-week silly marriage. They were married in 2008 but it’s 13 years they’ve been together.

“Their marriage was as stable as you can be. He’s going to wake up and find he’s thrown that away. He’s going to think, ‘What have I done?’”

Liam, a passionate Manchester City fan, already had three kids with three different women before this week’s revelations.

Just months after he married actress Patsy Kensit, 45, in 1997 he had a fling with singer Lisa Moorish, 40.

She gave birth to their daughter Molly, now 15, in 1998.

Liam and Patsy had son Lennon before their turbulent three-year marriage ended in 2000. Liam had son Gene with Nicole in 2001 after assuring her he had finally learned the error of his ways.